Cognitive factors as mediators of the relationship between childhood trauma and depression symptoms: the mediating roles of cognitive overgeneralisation, rumination, and social problem-solving

ABSTRACT

Background: Childhood trauma has negative immediate and long-term impacts on depression. Questions remain, however, regarding the cognitive factors influencing this relationship. This study aimed to investigate the role of three cognitive factors – cognitive overgeneralisation, rumination and social problem-solving – as mediating factors in the relationship between childhood trauma and symptoms of depression.

Methods: We conducted a cross-sectional study in Iran from March to July 2023. Participants (N = 227; Mean age 32.44 ± 8.95 years) with depression completed measures of childhood trauma, depression, self-overgeneralisation, cognitive errors, memory specificity, rumination and social problem-solving. The conceptual model was assessed using structural equation modelling.

Results: Structural equation modelling indicated that childhood trauma had a positive direct effect on depression symptoms. Childhood trauma had a positive indirect effect on depression symptoms through both self-overgeneralisation and rumination and a negative indirect effect on depression through effective social problem-solving strategies.

Conclusions: The findings suggest increased exposure to childhood trauma may be associated with elevated depression and self-overgeneralisation, rumination, and effective social problem-solving strategies may play an important role in this relationship. These findings hold potential implications for those working with patients with depression and a history of childhood trauma.

HIGHLIGHTS

• Since the relationship between childhood trauma and depression is not straightforward, the study addresses a significant gap in the understanding of the relationship between childhood trauma and depression symptoms by focusing on cognitive factors as potential mediators among depressed patients.

• Childhood trauma not only has a direct positive effect on depression symptoms but also indirectly influences depression through self-overgeneralisation and rumination, which contribute to elevated depression, while effective social problem-solving strategies act as a protective factor, leading to decreased depression symptoms.

• The significance of above cognitive overgeneralisation factors in shaping the relationship between childhood trauma and depression symptoms suggests that therapeutic interventions targeting these cognitive factors might be hold promise in improving mental health outcomes for this vulnerable population.

Antecedentes: El trauma infantil tiene impactos negativos inmediatos y a largo plazo en la depresión. Sin embargo, quedan interrogantes sobre los factores cognitivos que influyen en esta relación. Este estudio tuvo como objetivo investigar el papel de tres factores cognitivos (sobregeneralización cognitiva, rumiación y resolución de problemas sociales) como factores mediadores en la relación entre el trauma infantil y los síntomas de depresión.

Métodos: Realizamos un estudio transversal en Irán de marzo a julio de 2023. Los participantes con depresión (N = 227; edad media 32,44 ± 8,95 años) completaron medidas de trauma infantil, depresión, auto-sobregeneralización, errores cognitivos y especificidad de la memoria, rumiación y resolución de problemas sociales. El modelo conceptual se evaluó mediante modelos de ecuaciones estructurales.

Resultados: El modelo de ecuaciones estructurales indicó que el trauma infantil tuvo un efecto directo positivo sobre los síntomas de depresión. El trauma infantil tuvo un efecto indirecto positivo sobre los síntomas de depresión a través de la sobregeneralización y la rumiación y un efecto indirecto negativo sobre la depresión a través de estrategias efectivas de resolución de problemas sociales.

Conclusiones: Los hallazgos sugieren que una mayor exposición al trauma infantil puede estar asociada con una depresión elevada y la sobregeneralización, la rumiación y las estrategias efectivas de resolución de problemas sociales pueden desempeñar un papel importante en esta relación. Estos hallazgos tienen implicancias potenciales para quienes trabajan con pacientes con depresión y antecedentes de trauma infantil.

KEYWORDS:

• Childhood traumatic experiences
• childhood maltreatment
• major depressive disorder
• self-overgeneralisation
• overgeneralisation across situations
• overgeneral autobiographical memory
• rumination
• problem-solving

PALABRAS CLAVE:

• Experiencias traumáticas infantiles
• maltrato infantil
• trastorno depresivo mayor
• auto-sobregeneralización
• sobregeneralización entre situaciones
• memoria autobiográfica excesiva
• rumiación
• resolución de problemas

Depression is one of the most prevalent and disabling psychiatric disorders worldwide (World Health Organization, 2017). It contributes significantly to the Global Burden of Disease (Li, Xu, et al., 2022) and accounts for 1.85% of disability-adjusted life-years (Vos et al., 2020). It has long been recognised that depression results from both psychological and biological factors (Godlewska & Harmer, 2021), with one fundamental psychological factor being childhood trauma and trauma (Larsen, 2023). Childhood trauma is associated with the presence, severity and maintenance of depressive disorders (Danese & Widom, 2023; Lippard & Nemeroff, 2022; Mao et al., 2023). Despite this association being well-established, research is still needed to examine the cognitive and emotional factors that may play a role in the relationship between childhood trauma and depression. This study aimed to examine three such factors – cognitive overgeneralisation, rumination and social problem-solving.

The Diathesis-Stress Model suggests that an increase in stress can make individuals more vulnerable to developing depression (Ingram et al., 1998). Childhood trauma is recognised as a distal stress (occurring before the onset of depressive symptoms) that can lead to the development of depression (Harkness, 2023). The Diathesis-Stress Model outlines that preexisting cognitive vulnerability factors contribute to depressive responses to negative life events (Ingram et al., 2011). There is evidence that cognitive errors, attribution styles, and other cognitive vulnerabilities may interact with life stress and represent possible etiological factors for depression (Dozois & Hayden, 2022; Taylor, 2004). Therefore, it is well-established that cognitive factors, such as cognitive distortions and attribution styles, can interact with life stress and childhood trauma, potentially contributing to the development of depression (Klumparendt et al., 2019; Li, Tu, et al., 2022); cognitive overgeneralisation, rumination, and social problem-solving may be three such concepts.

Cognitive overgeneralisation is a consistent cognitive phenotype observed in individuals with depression (Ren et al., 2022). It occurs in various cognitive domains, including overgeneral thinking and overgeneral memory. Overgeneral thinking can relate to the self and situations; both playing a central role in depression (Raes et al., 2023; Van Lier et al., 2015). Self-overgeneralisation can lead to a pervasive sense of worthlessness or hopelessness, as individuals apply a specific negative event to their entire self-concept (Thew et al., 2017). Situation-overgeneralisation refers to a response to specific situations with overly broad attributions (Carver & Ganellen, 1983). Those with depression tend to have higher levels of negative overgeneralisation and lower levels of positive overgeneralisation (e.g. Klar et al., 1997; Raes et al., 2023; van den Heuvel et al., 2012). Overgeneral autobiographical memory (OGM) is strongly associated with depression (Matsumoto & Hallford, 2023; Weiss-Cowie et al., 2023) and plays a significant role in its onset and maintenance (Fernández-Pérez et al., 2023; Matsumoto et al., 2023). OGM retrieval refers to the tendency to recall more general autobiographic memories instead of specific autobiographic memories (Gandolphe et al., 2013). In depression, there is an apparent lack of specificity in the significant aspects of recollected adverse events (Hitchcock et al., 2020). Two meta-analyses, including 15 and 32 studies, concluded that OGM predicts depression symptoms, especially among clinical samples (Barry et al., 2021; Sumner et al., 2010). Of relevance to this study, Griffith et al. (2016) demonstrated that patients with childhood physical abuse and depression had difficulties providing specific memories.

Another fundamental cognitive component associated with depression is rumination. Rumination refers to repetitive and passive thinking that engages the attention of individuals on their depressive symptoms and the possible causes and consequences of those symptoms (Nolen-Hoeksema, 1991). Instead of processing emotion, rumination, as an unhealthy coping process, fosters undesirable self-related thoughts to manage emotion (Samtani & Moulds, 2017). According to Response Style Theory, rumination exacerbates negative mood states by elevating the perceived importance of the stressor (Nolen-Hoeksema, 1991). Rumination is likely to have a positive predictive effect on the evolution, severity, maintenance, and recurrence of depression and predicts the onset of depressive episodes (Stange et al., 2016). The relationship between rumination and childhood trauma and depression has been indicated in some studies (Deguchi et al., 2021; Masuya et al., 2023; Muñoz & Hanks, 2021). These studies have shown greater childhood trauma leads to higher levels of depression by increasing rumination. Wang et al. (2023) showed that rumination moderated the relationship between childhood trauma and depression. Mao et al. (2023) demonstrated that rumination partially mediated the effect between childhood trauma and trait depression, suggesting the negative influence of childhood trauma on depression was influenced by ruminative levels.

Finally, lack of ability to solve social problems plays a crucial role in the onset and persistence of depression (Noreen & Dritschel, 2022). People generate effective solutions to everyday problems through social problem-solving (Chang et al., 2004). Patients with depression may employ less effective strategies for interpersonal situations (Chang et al., 2020; Nezu et al., 2023). In a longitudinal study, Hasegawa et al. (2018) found that rumination and impulsive/careless problem-solving styles intensified depression. Noreen and Dritschel (2022) found that individuals with depression were less effective at generating social solutions than non-depressed individuals.

1. Current study

This study aimed to explore the mediating roles of cognitive overgeneralisation (including self, situation and autobiographical memory), rumination and social problem-solving in the relationship between childhood trauma and depression symptoms (Figure 1). As far as we are aware, this is the first study to directly examine whether cognitive problems, such as cognitive overgeneralisation, rumination and social problem-solving, mediate the relationship between childhood trauma and depression symptoms. This study is important, particularly in Iran, whereby childhood trauma is complicated and due to cultural and social reasons (e.g. low levels of reporting, tolerating and normalising child abuse, fear of stigma, children not being aware of their rights, and families having no desire to reveal child abuse) children have limited opportunities to be educated about trauma, families keep quiet when child maltreatment occurs (Dehghan Manshadi et al., 2023). Consequently, those who are maltreated as children in Iran potentially have heightened on-going psychological problems and there is a need for research on factors associated with child maltreatment to inform the development of specific and effective treatments (Dehghan Manshadi et al., 2023).

Figure 1. Conceptual model of associations between childhood maltreatment and depression symptoms: the mediate role of cognitive overgeneralisation, social problem-solving, rumination.

2. Method

2.1. Participants

Participants (N = 227) were outpatients with clinical depression and were recruited from two psychiatric clinics in Shiraz City, Iran, between March to July 2023. These clinics provide a range of services, including diagnostic evaluations, medication management, and psychotherapy. One of the most essential characteristics of these psychiatry clinics is the availability of experienced and qualified psychiatrists who are trained in diagnosing and treating mental health disorders. Inclusion criteria were: (i) meeting diagnosis of major depressive disorder (MDD) in accordance with the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition, MDD (as diagnosed by an experienced psychiatrist); (ii) aged between 18 and 65 years; and (iii) at least primary school education. Exclusion criteria were: (i) comorbidity with another psychiatric disorder; (ii) drug or alcohol dependence; (iii) presence of neurological or organic injury; and (iv) severe physical illness. The minimum R-squared method was used to estimate the minimum sample size. By setting power at 80%, the maximum number of arrows pointing at a latent variable = 6, minimal R² = 0.1, α = 0.05, the sample size of 157 was determined (Hair et al., 2014). To ensure we met this estimate, we aimed to recruit 240 patients with depression. In the final sample, 227 participants (162 women and 65 men) remained after removing incomplete and unreliable questionnaires or not meeting the eligibility criteria.

2.2. Procedure

The current cross-sectional study was approved by the Ethics Committee of the University of Isfahan (IR.UI.REC.1402.064). All participants provided written informed consent. Participants completed the following measures.

2.3. Measures

2.3.1. Childhood trauma questionnaire (CTQ)

The 28-item Childhood Trauma Questionnaire developed by Bernstein et al. (2003). This questionnaire is a screening tool for identifying individuals with experiences of childhood abuse and neglect that can be used for adults. It assesses five types of childhood trauma, including sexual abuse, physical abuse, emotional abuse, and emotional and physical neglect. Participants rate the severity/frequency of events on 5-point Likert-scales (1 = never true, 5 = very often/always true). The CTQ has shown strong internal consistency (Cronbach's alpha = .91) (Scher et al., 2001), exhibited excellent inter-rater reliability for both the total score and individual subscale scores (ICC ranging from .89 to .94) and demonstrated good test-retest reliability (r = .79–.86 over an average period of four months). The scale's consistent five-factor structure was evident in a diverse range of samples, indicating the appropriateness and validity of the childhood trauma subscales (Bernstein et al., 1994). In Iran, Ebrahimi et al. (2014) have reported Cronbach's alpha for the CTQ as ranging from .81 to .98 for its five components. Cronbach's alpha in the current research ranged from .74–.89.

2.3.2. The beck depression inventory-II (BDI-II)

The BDI-II (Beck, 1996) is a 21-item self-report measure of symptoms of depression, with total score ranging from 0 to 63 and higher scores indicating more severe symptoms. It has been established that depression can be classified as minimal (0–13), mild (14–19), moderate (20–29) and severe (29–63) (Beck, 1996). The BDI-II has exhibited good internal consistency (Cronbach's alpha = .92), test-retest reliability (r = .93) and convergent validity (Beck et al., 1996). The psychometric properties of the BDI-II among Iranian patients with major depressive disorder were acceptable; internal consistency (.91) and convergent validity (.87) (Stefan-Dabson et al., 2007). In this study Cronbach's alpha was .73.

2.3.3. Cognitive overgeneralisation

2.3.3.1. Overgeneralisation subscale of the attitudes toward self scale (ATS-OG)

The ATS-OG is one of the three subscales of the Attitudes Towards Self (Carver & Ganellen, 1983). The ATS-OG contains seven items that assess the tendency to generalise from one failure to a broader sense of self-worth. Items are rated from 1 (extremely untrue) to 5 (extremely true). Carver et al. (1988) demonstrated that the ATS-OG scale was related to depression. In the current study, this scale had good internal consistency (Cronbach alpha = .88). Furthermore, Kaiser-Meyer-Olkin (KMO) and Bartlett’s Test of Sphericity, employed to assess the adequacy of the sample and the suitability of the data for factor analysis, demonstrated that the sample size was adequate and the variables possessed the necessary characteristics for effective factor analysis (KMO = .90, χ² = 722.19, df  = 21). The total variance explained was 59.45% for one factor.

2.3.3.2. Overgeneralisation subscale of the cognitive errors questionnaire-revised (CEQ-R-OG)

The CEQ-R-OG uses three vignettes, describing three broad life experiences, assessing overgeneralisation across situations (Moss-Morris & Petrie, 1997). Each vignette ends with an overgeneralised thought and participants use scales rated from 1 (not at all like I would think) to 5 (almost exactly like I would think) to indicate how similar the thought is to how they would typically think in such a situation. Internal consistency has been found to be good (Raes et al., 2023) and was excellent in the current study (Cronbach’s alpha = .91). The KMO and Bartlett’s Test of Sphericity were appropriate (KMO = .75, χ² = 459.41, df = 3). One factor explained a total variance of 84.98%.

2.3.3.3. Autobiographical memory test (AMT)

Williams and Broadbent (1986) developed the AMT to test autobiographical memory specificity. The Persian version of AMT was used in this study (Neshat-Doost et al., 2013). A total of 18 Persian words were presented to participants, including positive (e.g. ceremony جشن ), negative (e.g. fight دعوا ), and neutral (e.g. book کتاب ) words. After reading each word aloud, participants had 30 s to recall a specific memory. Participants were asked to recall something that happened at a specific time on a particular day and the event could be recent or in the past. Three words were given as practice. An event that lasted one day or less was defined as a specific memory. Nonspecific memories were classified as either extended (events lasting longer periods of time) or categorical (events occurring repeatedly) memories. Participants classified their responses as ‘no memory’ if they were unable to recall a memory or talked about something unrelated to memories. The psychometric properties of the AMT are adequate (Griffith et al., 2009; Neshat-Doost et al., 2013). In the present study, Cronbach alpha was .87.

2.3.4. Ruminative response scale (RRS-10)

The RRS is a 10-item questionnaire assessing rumination (Nolen-Hoeksema, 1991). It contains two subscales: reflection and brooding, with items being rated from 1 (never) to 4 (always), with higher scores indicating a greater tendency to ruminate. The RRS-10 has good internal consistency (Cronbach's alpha = .72 and .77 for the reflection and brooding subscales, respectively) and test-retest reliability (Lee & Kim, 2014). In this study internal consistency was good (Reflection Cronbach alpha = .75, Brooding Cronbach alpha = .77).

2.3.5. Means-ends problem-solving procedure (MEPS)

The MEPS assesses social problem-solving skills (Platt & Spivack, 1975a). The MPPS includes stories in which a protagonist faces a problem that is followed by a successful ending. Participants are expected to describe strategies for resolving the problem. Following the approach of Platt and Spivack (1975b), we used four stories in the abbreviated format. The effectiveness of responses were rated on 7-point Likert scales (not at all effective to extremely effective) (Marx et al., 1992). Good reliability was reported for MEPS (Raes et al., 2005). The validity and reliability of the Persian version of MEPS has been confirmed (Kaviani et al., 2005). In the present study, internal consistency was good (Effectiveness Subscale Cronbach alpha = .87; Means Subscale Cronbach Alpha = .78).

2.4. Data analyses

SPSS-22 was used to analyse the descriptive statistics. We tested our conceptual model using structural equation modelling (SEM) using Smart PLS-3 (Figure 1). First, we checked the normality distribution of all variables and conducted Pearson correlations. Mediating effects were tested by bootstrapping (1000 bootstrap draws) using 95% confidence intervals. In testing assumptions, it was found that all variables followed a normal distribution (with the exception of depression symptoms; kurtosis = 4.30) (West et al., 1995) (see Table 1). However, the Partial Least Squares regression (PLS) is not sensitive for normality assumption and sample size The Variance Inflation Factor (VIF) did not indicate the presence of severe multicollinearity (see Supplemental Table 1).

Table 1. Descriptive indicators of variables.

		Mean ± SD	Skewness	Kurtosis
Childhood trauma	Emotional abuse	10.03 ± 4.34	0.‏85	−0.‏25
	Physical abuse	8.56 ± 4.98	1.‏39	0.‏79
	Sexual abuse	8.57 ± 4.44	0.‏97	−0.‏25
	Emotional neglect	12.41 ± 4.95	0.‏29	−0.‏91
	Physical neglect	9.59 ± 4.28	0.‏81	−0.‏48
Self-overgeneralisation		15.46 ± 5.08	0.15	0.31
Situation-overgeneralisation		7.33 ± 3.7	0.49	−1
General autobiographical memory		9.69 ± 4.96	−0.36	−0.87
Rumination-reflection		14.15 ± 3.57	−0.40	−0.43
Rumination-brooding		14.41 ± 3.61	−0.66	0.06
MEPS effectiveness		16.95 ± 5.6	0.49	−1.00
MEPS means		6.07 ± 3.17	0.31	−0.12
Depression symptoms		28.73 ± 3.36	1.85	4.3

3. Results

3.1. Participant characteristics

The mean age of the sample was 32.44 years (SD = 8.95). The sample comprised of 65 men and 162 women. A total of 26 (11.45%) participants reported that their highest level of education was a high school diploma, 52 participants (22.91%) reported they had a diploma, 112 (49.34%) participants had a Bachelor's degree, and 37 (16.3%) of participants had a Master's degree. Descriptive variables are presented in Table 1.

3.2. Validity of measurement models

Reliability (Composite Reliability (CR) and Cronbach alpha) and validity (Factor loads, Average Variance Extracted (AVE), and Rho_A) were calculated to evaluate the suitable and favourable conditions of measurement models. As the Cronbach's alpha and composite reliability values for all variables was greater than .70 (Malhotra, 2010), the measurement instruments demonstrated satisfactory internal consistency. Additionally, we found the variables meet the necessary criteria (CR > .6, AVE > .5, and Rho_A > .7; Hair et al., 2021) for convergent validity (Table 2).

Table 2. Convergent validity indicators.

	Cronbach alpha	CR	AVE	Rho_A
Childhood trauma	.90	.90	.65	.90
Self-overgeneralisation	.88	.88	.52	.89
Situation-overgeneralisation	.91	.91	.79	.95
General autobiographical memory	.87	.88	.78	.87
Rumination-reflection	.75	.78	.78	.76
Rumination-brooding	.77	.78	.62	.79
MEPS effectiveness	.87	.87	.62	.87
MEPS means	.78	.74	.63	.71
Depression symptoms	.73	.69	.69	.70

The results of standardised estimates of the structural model (Figure 2) revealed all study factor's representative items possessed a standard coefficient above .40, signifying a desirable model.

Figure 2. Standardised estimates of the structural model.

The Fornell-Larcker criterion and Heterotrait-Monotrait Ratio (HTMT) assessed divergent validity. Based on the Fornell-Larcker matrix, the validity of the research model was confirmed, as the Square Root of AVE for each construct in the model was greater than its correlation with other constructs. Furthermore, the values on the main diameter of the matrix surpassed all the values in the corresponding column for each construct in the model (Supplemental Table 2). As the criterion values of HTMT were below 0.9 (Gold et al., 2001), the model's divergent validity was confirmed (Supplemental Table 2). Supplemental Table 3 indicates that each item's factor loading has the strongest correlation with its corresponding variable, suggesting that the model's underlying variables are adequately distinct from one another.

3.3. Mediation structural model

The direct and indirect effects of the model are presented in Table 3 and Figure 2. The direct effects of childhood trauma on depression symptoms (β = .37, p < .001), overgeneral autobiographical memory (β = .62, p < .001), self-overgeneralisation (β = .57, p < .001), reflection rumination (β = .48, p < .001), brooding rumination (β = .45, p < .001), and MEPS-effectiveness (β = −.60, p < .001), were significant. Self-overgeneralisation (β = .16, p < .05), reflection rumination (β = .20, p < .01), brooding rumination (β = .45, p < .05), and MEPS-effectiveness (β = −.14, p < .01), all had a direct effect on depression symptoms. Indirect effects of childhood trauma via self-overgeneralisation (β = .11, p < .01), reflection rumination (β =  .08, p < .01), brooding rumination (β = .07, p < .01), and MEPS-effectiveness (β = .08, p < .05), were significantly associated with depression symptoms. Finally, total effects of childhood trauma on depression symptoms was significant, β = .67, p < .001.

Table 3. Study tested hypotheses.

	Beta (β)	T value	p value	Results
Childhood trauma > Depression	.37	3.786	<.001	Accepted
Childhood trauma > Self- overgeneralisation	.57	11.53	<.001	Accepted
Childhood trauma > Situation- overgeneralisation	.1	1.35	.17	Not accepted
Childhood trauma > General autobiographical memory	.62	12.61	<.001	Accepted
Childhood trauma > Rumination _reflection	.48	9.47	<.001	Accepted
Childhood trauma > rumination_brooding	.45	9.07	<.001	Accepted
Childhood trauma > MEPS effectiveness	−.60	13.67	<.001	Accepted
Childhood trauma > MEPS means	−.02	0.17	.86	Not accepted
Self-overgeneralisation > Depression	.16	2.12	.03	Accepted
Situation-overgeneralisation > Depression	.09	1.68	.09	Not accepted
General autobiographical memory > Depression	−.06	1.01	.31	Not accepted
Rumination _reflection > Depression	.20	4.13	<.001	Accepted
Rumination_brooding > Depression	.10	2.80	.005	Accepted
MEPS effectiveness > Depression	−.14	2.70	.007	Accepted
MEPS means > Depression	−.06	0.76	.44	Not accepted
Childhood trauma > Self-overgeneralisation > Depression	.‏09	2.‏02	.04	Accepted
Childhood trauma > Rumination _reflection > Depression	.1	3.09	.002	Accepted
Childhood trauma > Rumination_brooding > Depression	.05	2.‏75	.006	Accepted
Childhood trauma > MEPS effectiveness > Depression	.08	2.01	.‏04	Accepted

4. Discussion

This study aimed to examine how cognitive overgeneralisation, rumination, and social problem-solving act as mediators in the relationship between childhood trauma and depression symptoms among depressed patients in Iran. SEM analysis demonstrated that childhood trauma has an effect on depression symptoms both directly and indirectly through self-overgeneralisation, rumination (reflective and brooding), and effective social problem-solving strategies.

As the experimental model of the research indicates, childhood trauma has a direct and positive effect on depression symptoms. The relationship between childhood trauma and depression is widely recognised (Danese & Widom, 2023; Kuzminskaite et al., 2021; Souama et al., 2023; Watters et al., 2023). Li et al. (2023) demonstrated that the risk of developing depression is heightened when individuals experience any form of childhood trauma, such as physical abuse, sexual abuse, emotional abuse, or neglect. A six-year longitudinal study demonstrated that individuals who experienced childhood trauma, particularly severe childhood trauma, exhibited notably elevated levels of depressive symptoms compared to those without such trauma (Kuzminskaite et al., 2022). Moreover, these effects were consistent across different types of childhood trauma and remained significant over the entire six-year period of observation (Kuzminskaite et al., 2022). Our study provides further support, among an Iranian sample, of the association between childhood trauma and depression.

In further support of our second finding, childhood trauma relations with depression symptoms positively through self-overgeneralisation. Experiencing childhood trauma can lead to the formation of cognitive patterns that influence self-perception (Steenkamp et al., 2023). Individuals with childhood trauma are more likely to view themselves negatively (Burnash et al., 2010) and self-overgeneralisation may lead to the development of negative self-schemas, influencing how individuals expect themselves to think, feel, and act in particular settings or situations (Raes et al., 2023). Our findings are consistent with previous research that shows the relationship between childhood traumas, depression symptoms with negative self-schemas (Cherry & Lumley, 2019; Collins et al., 2023; Jopling et al., 2020). Children who exhibit persistent negative self-perceptions resulting from self-overgeneralisation are at a higher risk of developing low self-esteem, feelings of hopelessness, and a sense of helplessness, commonly observed in individuals with depression (e.g. Raes et al., 2023). This may be particularly pertinent in cultures with robust traditional and social norms, like Iran, whereby children who have endured abuse may unconsciously internalise a sense of guilt and responsibility for their experiences (Dehghan Manshadi et al., 2023). This could lead individuals to develop negative self-perceptions due to the predominant emphasis on family values rather than the child's trauma, the importance of respecting parents and adhering to traditional cultural norms, and the encouragement of families and communities to maintain silence on such matters (Dehghan Manshadi et al., 2023). Negative self-schema, in turn, may increase the risk of depressive symptoms (Collins et al., 2023).

Our findings that rumination (reflection and brooding) mediated the relationship between childhood trauma and depression symptoms aligns with previous studies (Fang et al., 2023; Mansueto et al., 2021; Mao et al., 2023; Masuya et al., 2023). Childhood trauma is often challenging to openly talk about and tends to be repressed, so that it might resulting in the development of a ruminative pattern of thinking (Kim et al., 2017). Rumination serves as an automatic coping mechanism utilised unconsciously by individuals aiming to process these distressing experiences (Smith & Alloy, 2009). Nevertheless, Individuals who engage in rumination, specifically reflecting on the meaning and causes of threatening events (Johnson et al., 2008), tend to have prolonged periods of depressed mood and longer periods of negative affect, ultimately leading to more persistent negative mood states (Roberts et al., 2020). That is, rather than leading to problem-solving (Michl et al., 2013), rumination sustains negative emotions, hindering the ability to overcome the impact of trauma, which can lead to feelings of hopelessness, helplessness, worthlessness, sadness, and other depression symptoms. Our results extend these previous findings by evaluating these associations among patients with depression in Iran.

Childhood trauma was also negatively related to a more effective social problem-solving strategies, which in turn was negatively associated with depressive symptoms. This significant result is consistent with previous research findings (Allan, 2015; Bell & Higgins, 2015; Demirbaş, 2018). Alvarez et al. (2022) found that social problem-solving skills were identified as a mediator in the relationship between adverse childhood experiences of community violence and physical abuse and depression among Latina immigrants. Childhood trauma can have negative effects on social relationships, particularly in the context of family dynamics (Levendosky et al., 1995; Steenkamp et al., 2023). Individuals who have experienced childhood trauma are more likely to face challenges in establishing healthy relationships than their counterparts. This is attributed to factors such as reduced levels of trust, inadequate emotional regulation abilities, and the adoption of maladaptive coping mechanisms (Poole et al., 2018). Social problem-solving, which involves finding effective strategies to cope with challenges (D’Zurilla et al., 2002), can be impaired by childhood trauma (Pfaltz et al., 2022). In turn, the interruption of effective social problem-solving solutions may cause to start or augment the depression symptoms. Difficulties in social skills serve as a vulnerability factor for depression disease (Thoma et al., 2015). In other words, Individuals with impaired social problem-solving might experience depression symptoms, as Thoma et al. (2015) confirmed in their study. They showed that individuals with depression often display deficiencies in solving social problems, generating fewer effective solutions than normal individuals.

4.1. Limitations

The study had some limitations. First, it is important to avoid inferring causal conclusions as the study adopted a cross-sectional design. Second, the data relies on self-reported measures collected retrospectively, which are known to be prone to bias (Althubaiti, 2016). Sole reliance on self-reports, which may introduce negative bias and create dependencies among the measured constructs. To enhance the study's credibility, incorporating a behavioural task to assess cognitive performance and/or state would have been beneficial. Third, the limited number of male participants prevents us from conducting in-depth analyses regarding gender differences. Consequently, the findings should be generalised cautiously. Additionally, it is possible that this model is gender-dependent and findings may vary between men and women.

4.2. Conclusion

In summary, self-overgeneralisation, rumination (including reflection and brooding), and effectiveness in social problem-solving mediated the relationship between childhood trauma and depression symptoms. The results of this study could have important clinical implications. In order to prevent the adverse outcomes of childhood trauma among depressed Iranian patients, counsellors could target self-overgeneralisation and rumination to reduce negative cognitive patterns and develop effective social problem-solving solutions, which in turn may assist with managing negative emotions and reduce depression symptoms.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, upon reasonable request.